Laparoscopic clamp load measuring devices

ABSTRACT

A surgical end effector comprising a first jaw, a second jaw, a strain gauge, and a thickness measurement cartridge is disclosed. The first jaw comprises a first jaw undersurface. The first jaw is selectively movable relative to the second jaw. The strain gauge is supported by the second jaw and configured to communicate with a central processing unit configured to calculate thickness of tissue. The thickness measurement cartridge comprising a cartridge body and a pivot formation. The cartridge body is configured to be removably supported in the second jaw such that a tissue contacting surface thereon faces the first jaw undersurface. The pivot formation on the cartridge body facilitated pivotal movement of the cartridge body relative to the second jaw.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application claiming priority under35 U.S.C. § 120 to U.S. patent application Ser. No. 11/729,008, entitledLAPAROSCOPIC TISSUE THICKNESS AND CLAMP LOAD MEASURING DEVICES, filedMar. 28, 2007, which issued on Nov. 25, 2014 as U.S. Pat. No. 8,893,946,the entire disclosure of which is hereby incorporated by referenceherein.

FIELD OF THE INVENTION

The present invention relates in general to laparoscopic and endoscopicsurgical instruments and, more particularly, to endoscopic surgicaldevices and grasping devices configured to enable the surgeon to measuretissue thickness and clamping loads.

BACKGROUND OF THE INVENTION

Endoscopic surgical instruments are often preferred over traditionalopen surgical devices since a smaller incision tends to reduce thepost-operative recovery time and complications. Consequently,significant development has gone into a range of endoscopic surgicalinstruments that are suitable for precise placement of a distal endeffector at a desired surgical site through a cannula of a trocar. Thesedistal end effectors engage the tissue in a number of ways to achieve adiagnostic or therapeutic effect (e.g., endocutter, grasper, cutter,staplers, clip applier, access device, drug/gene therapy deliverydevice, and energy device using ultrasound, RF, laser, etc.).

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument commonly includes aplurality of reciprocating wedges which, when driven distally, passthrough openings in the staple cartridge and engage drivers supportingthe staples to effect the firing of the staples toward the anvil.

When using an endocutter during endoscopic surgery, it is oftendifficult for the surgeon to determine the thickness of the tissue thatthey are about to transect. The thickness of the tissue determines thetype of cartridge/staple they need in order to properly seal thetransection. Often times, the surgeon must make the thicknessdetermination based upon their visual observations of the tissue on amonitor or, if possible, they use their hands to feel the thickness ofthe tissue.

Another type of device that is commonly employed during laparoscopicsurgery is known as a grasper. Such graspers typically have a pair ofopposing jaws that are used to grasp tissue or portions of othersurgical instruments during the surgical procedure. Such graspingdevices, however, also lack means for determining tissue thicknesses. Inaddition, the jaw arrangements employed by such graspers are oftenill-suited to effectively grip and manipulate other surgical instrumentsused during the operation.

Consequently, a significant need exists for a laparoscopic device thatwould permit a surgeon to accurately and repeatably measure tissuethickness to enable the surgeon to select a proper staple cartridge toperform a transection. There is a further need for graspers that havetissue thickness measuring capabilities and jaws designed to effectivelygrasp other surgical instruments therebetween.

The foregoing discussion is intended only to illustrate some of theshortcomings present in the field of the invention at the time, andshould not be taken as a disavowal of claim scope.

SUMMARY

In various embodiments, an end effector for use with a surgicalinstrument is disclosed. The end effector comprises a first jaw, asecond jaw, a strain gauge, a central processing unit, and a cartridge.The first jaw and the second jaw are configured to clamp tissue inresponse to a closing motion applied to the first jaw to move the firstjaw between an open position, a partially clamped position, and a fullyclamped position. The strain gauge is configured to generate a firststrain reading and a final strain reading as the tissue is clamped. Thecentral processing unit is configured to calculate thickness of thetissue by comparing the first strain reading and the final strainreading. The cartridge comprises a cartridge body and a protrusion. Thecartridge body is configured to be removably supported in the second jawand defines a cartridge deck surface. The protrusion extends from thecartridge deck surface. An end of the protrusion comprises a singlepoint on the cartridge body that is closest to the first jaw to focus aload applied to the cartridge toward the strain gauge.

In various embodiments a surgical end effector comprising a first jaw, asecond jaw, a strain gauge, and a thickness measurement cartridge isdisclosed. The first jaw comprises a first jaw undersurface. The firstjaw is selectively movable relative to the second jaw. The strain gaugeis supported by the second jaw and configured to communicate with acentral processing unit configured to calculate thickness of tissue. Thethickness measurement cartridge comprising a cartridge body and a pivotformation. The cartridge body is configured to be removably supported inthe second jaw such that a tissue contacting surface thereon faces thefirst jaw undersurface. The pivot formation on the cartridge bodyfacilitated pivotal movement of the cartridge body relative to thesecond jaw.

In various embodiments a surgical end effector comprising a first jaw, asecond jaw, and a thickness measurement cartridge is disclosed. Thefirst jaw comprises a first jaw undersurface. The first jaw isselectively movable relative to the second jaw. The thicknessmeasurement cartridge comprises a cartridge body, a strain gauge, and anupstanding flexible probe. The cartridge body is configured to beremovably supported in the second jaw. The cartridge body defines a decksurface. The strain gauge is supported by the cartridge body. Theupstanding flexible probe arm is operably coupled to the strain gaugeand extends above the deck surface such that the flexible probe arm isproximal to a tissue contact area of the first jaw undersurface.

In another aspect of the present invention, there is provided a surgicalinstrument that may comprise a handle assembly and a pair of opposingjaws that are operably coupled to the handle assembly. The opposing jawsmay be selectively movable between open and closed positions forclamping tissue therebetween. The surgical instrument may furtherinclude a closure drive that is operably supported by the handleassembly for selectively applying opening and closing motions to thepair of opposing jaws. An output generator may cooperate with theclosure drive to display reference indicia that corresponds to athickness of the tissue clamped between the pair of opposing jaws.

These and other objects and advantages of the present invention shall bemade apparent from the accompanying drawings and the descriptionthereof.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of the invention given above,and the detailed description of the embodiments given below, serve toexplain various principles of the present invention.

FIG. 1 is a perspective view of a surgical stapling and severinginstrument of various embodiments of the present invention;

FIG. 2 is a left side perspective view of an end effector embodiment ofthe present invention;

FIG. 3 is a cross-sectional view of the end effector of FIG. 2 with aportion of tissue clamped between the anvil and tissue measurementcartridge;

FIG. 4 is a cross-sectional view of the end effector of FIG. 3 takenalong line 4-4 in FIG. 3;

FIG. 5 is a schematic diagram of a strain gauge and operating systemarrangement of various embodiments of the present invention;

FIG. 6 is a cross-sectional view of another end effector embodiment ofthe present invention with tissue clamped between the anvil and thetissue measurement cartridge;

FIG. 7 is a schematic diagram of a strain gauge and operating systemarrangement of another embodiment of the present invention;

FIG. 8 is a side elevational view of a grasper embodiment of the presentinvention with the left hand side of the handle casing removed to showthe various components supported within the handle assembly;

FIG. 9 is an exploded assembly view of a portion of the grasper rodarrangement employed in the grasper embodiment depicted in FIG. 8;

FIG. 10 is a schematic view of various components of the grasperembodiment of FIG. 8 with the jaws thereof in an open position;

FIG. 11 is another schematic view of various components of the grasperembodiment of FIG. 8 with the jaws thereof clamping a portion of tissuetherebetween;

FIG. 12 is another schematic view of various components of the grasperembodiment of FIG. 8 with the jaws thereof in a fully closed position;

FIG. 13 is a right side elevational view of another grasper embodimentof the present invention;

FIG. 14 is a side elevational view of a jaw arrangement of otherembodiments of the present invention;

FIG. 15 is a side view of another surgical instrument embodiment of thepresent invention;

FIG. 16 is an exploded assembly view of a portion of the surgicalinstrument of FIG. 15;

FIG. 17 is a cross-sectional view of a handle assembly of the surgicalinstrument of FIGS. 15 and 16 with some components thereof shown insolid form for clarity;

FIG. 18 is a cross-sectional view of the surgical instrument of FIGS.15-17 in a fully closed and locked position with some components thereofshown in solid form for clarity;

FIG. 19 is another cross-sectional view of the surgical instrument ofFIGS. 15-18 in a fully open position with some components thereof shownin solid form for clarity;

FIG. 20 is another cross-sectional view of the surgical instrument ofFIGS. 15-19 in a fully closed position and with the release trigger in afully depressed position with some components thereof shown in solidform for clarity;

FIG. 21 is another cross-sectional view of the surgical instrument ofFIGS. 15-20 in a tissue clamping position with some components thereofshown in solid form for clarity;

FIG. 22 is a cross-sectional view of the surgical instrument of FIGS.15-21 in a position wherein the clinician is applying excessive clampingforce to the tissue with some components thereof shown in solid form forclarity; and

FIG. 23 is another cross-sectional view of the surgical instrument ofFIGS. 15-22 in a tissue clamping position wherein the user can read thereference indicia corresponding to a thickness “t” of the tissue clampedthereby.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those of ordinary skill in the art will understand that thedevices and methods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the various embodiments of the present invention is definedsolely by the claims. The features illustrated or described inconnection with one exemplary embodiment may be combined with thefeatures of other embodiments. Such modifications and variations areintended to be included within the scope of the present invention.

The present invention generally relates to methods and devices formeasuring the thickness of tissue to be transected or otherwisemanipulated during endoscopic and laparoscopic procedures. In oneexemplary embodiment, the measuring device can be employed in connectionwith an endocutter for transecting and stapling tissue. Such endocutterstypically include an end effector with opposing jaws that are adapted toreceive the target tissue therebetween. As will be described inconnection with one exemplary embodiment, the end effector is attachedto a handle assembly by an elongated shaft assembly. The handle assemblyis equipped with a closure trigger that enables the surgeon toselectively open and close the end effector jaws. The end effector isalso equipped with a firing drive system for driving a knife through thestaple cartridge and clamped tissue while also driving the stapleshoused within the staple cartridge into forming contact with an anvil.Other exemplary embodiments comprise a surgical device that has a pairof opposed jaws for simply manipulating and grasping tissue, othersurgical instruments, etc.

As the present Detailed Description proceeds, a person of ordinary skillin the art will appreciate that the surgical instruments describedherein can have a variety of configurations, and that one or more of thevarious tissue measurement features of the various embodiments of thepresent invention disclosed herein can be successfully used in a varietyof different grasping device/end effectors known in the art forgrasping/manipulating tissue or other objects. Thus, the term “surgicalinstrument” as used herein is intended to include any device that hasopposed movable jaws that come together to grasp, clamp, cut, dissect,staple, etc.

Turning to the Drawings, wherein like numerals denote like componentsthroughout the several views, FIGS. 1 and 2 depict a surgical staplingand severing instrument 10 that is capable of practicing various uniquebenefits of the present invention. The surgical stapling and severinginstrument 10 incorporates an end effector 12 that has a first jaw 14and a second jaw 16. In various embodiments, the second jaw 16 maycomprise elongate channel 17 and the first jaw may comprise an anvil 15that is pivotally attached to the elongate channel 17, forming opposingjaws for clamping tissue to be severed and stapled. Those of ordinaryskill in the art will understand that the exemplary endocutterembodiment depicted in the Figures comprises one endocutter version withwhich various embodiments of the present invention may be successfullyemployed. However, various embodiments of the present invention may beused in connection with a variety of different endocutter instruments.For example, various embodiments of the present invention may be used inconnection with those surgical instruments disclosed in U.S. Pat. No.6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAMFIRING MECHANISM, the disclosure of which is herein incorporated byreference.

As can be seen in FIG. 1, the end effector 12 may be coupled to a handleassembly 20 by an elongate shaft assembly 18. An implement portion 22,formed by the end effector 12 and shaft assembly 18, may beadvantageously sized for insertion through a trocar or smalllaparoscopic opening to perform an endoscopic surgical procedure whilebeing controlled by a surgeon grasping the handle assembly 20. Thehandle assembly 20 may include features that allow separate closuremotions and firing motions, lockouts to prevent inadvertent orill-advised firing of the end effector, as well as enabling multiplefiring strokes to effect firing (i.e., severing and stapling) of the endeffector 12 while indicating the degree of firing to the surgeon.

To these ends, a closure tube 24 of the shaft assembly 18 may be coupledbetween a closure trigger 26 (FIG. 1) and the anvil 15 to cause closureof the end effector 12. Within the closure tube 24, a frame 28 may becoupled between the elongate channel 17 and the handle assembly 20 tolongitudinally position and support the end effector 12. A rotation knob30 may be coupled with the frame 28, and both elements may be rotatablycoupled to the handle assembly 20. Thus, the surgeon can rotate the endeffector 12 by turning the rotation knob 30 which causes rotation of theclosure tube 24. The frame 28 extends through the closure tube 24 alongwith a firing rod 32 which is positioned for longitudinal movement andis operably coupled to a firing trigger 34. In the embodiment depictedin FIG. 1, the closure trigger 26 is distal to a pistol grip 36 of thehandle assembly 20 with the firing trigger 34 distal to both the pistolgrip 36 and closure trigger 26.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping a handle of an instrument.Thus, the end effector 12 is distal with respect to the more proximalhandle assembly 20. Analogous terms such as “front” and “back” similarlycorrespond respectively to distal and proximal. It will be furtherappreciated that for convenience and clarity, spatial terms such as“vertical”, “horizontal”, “up” and “down” are used herein with respectto the drawings. However, surgical instruments are used in manyorientations and positions, and these terms are not intended to belimiting and absolute.

The present invention is being discussed in terms of endoscopicprocedures and apparatus. However, use herein of terms such as“endoscopic”, should not be construed to limit the present invention toa surgical stapling and severing instrument for use only in conjunctionwith an endoscopic tube (i.e., trocar). On the contrary, it is believedthat the present invention may find use in any procedure where access islimited to a small incision, including but not limited to laparoscopicprocedures, as well as open procedures.

With particular reference to FIG. 3, the anvil 15 is pivotally coupledto the elongate channel 17 by a pair of laterally projecting anvil pivotpins 54 that are proximal to a vertically projecting anvil feature 56(FIG. 4). The anvil pivot pins 54 translate within kidney shapedopenings 58 in the elongate channel 17 to open and close anvil 15relative to elongate channel 17. The anvil feature 56 engages a tab 59(FIG. 1) extending inwardly in a tab aperture 60 on a distal end 62 ofthe closure tube 24. Thus, when the closure tube 24 moves proximallyfrom its open position, the tab 59 of the closure tube 24 draws theanvil feature 56 proximally, and the anvil pivot pins 54 follow thekidney shaped openings 58 of the elongate channel 17 causing the anvil15 to simultaneously translate proximally and rotate upward to the openposition. When the closure tube 24 moves distally, the tab 59 in the tabaperture 60 releases from the anvil feature 56 and the distal edge 64pushes on the anvil face 50, closing the anvil 15.

It should be appreciated that, although a nonarticulating shaft assembly18 is illustrated herein, applications of the present invention mayinclude instruments capable of articulation, such as those described inthree commonly owned U.S. patents and two commonly owned U.S. Patentapplications, the disclosure of each being hereby incorporated byreference in their entirety: (1) U.S. Pat. No. 7,111,769, issued Sep.26, 2006, entitled SURGICAL INSTRUMENT INCORPORATING AN ARTICULATIONMECHANISM HAVING ROTATION ABOUT THE LONGITUDINAL AXIS; (2) U.S. Pat. No.6,981,628, issued Jan. 3, 2006, entitled SURGICAL INSTRUMENT WITH ALATERAL-MOVING ARTICULATION CONTROL; (3) U.S. Pat. No. 7,055,731, issuedJun. 6, 2006 entitled SURGICAL STAPLING INSTRUMENT INCORPORATING ATAPERED FIRING BAR FOR INCREASED FLEXIBILITY AROUND THE ARTICULATIONJOINT; (4) U.S. Patent Publication No. 2005/0006429 entitled SURGICALSTAPLING INSTRUMENT HAVING ARTICULATION JOINT SUPPORT PLATES FORSUPPORTING A FIRING BAR, U.S. patent application Ser. No. 10/615,971,filed Jul. 9, 2003, now U.S. Pat. No. 6,964,363; and (5) U.S. PatentApplication entitled SURGICAL STAPLING INSTRUMENT INCORPORATING ANARTICULATION JOINT FOR A FIRING BAR TRACK, U.S. patent application Ser.No. 10/615,962, filed Jul. 9, 2003, now U.S. Pat. No. 6,786,382. Thoseof ordinary skill in the art will readily understand, however, that theunique and novel aspects of various features of the present inventionmay be employed in connection with still other types of articulatingsurgical instruments without departing from the spirit and scope of thepresent invention.

With reference to FIGS. 2 and 3, the elongate channel 17 is configuredto removably receive a thickness measurement cartridge 100 therein.Thickness measurement cartridge 100 may resemble a conventional staplecartridge. However, thickness measurement cartridge 100 lacks thestaples and staple firing drivers and may also differ from aconventional staple cartridge in at least the manners described below.In particular, the body portion 102 of the thickness measurementcartridge 100 may have an upstanding clamping nodule 110 that is formedon a distal end 101 of the cartridge 100. The clamping nodule 110 may beso oriented on the distal end 101 of the cartridge 100 such that whenthe cartridge 100 is installed in the elongate channel 17, the clampingnodule 110 is located over a first conventional strain gauge 120 that ismounted within the elongate channel 17. The purpose of the first straingauge 120 will be discussed in further detail below.

As can also be seen in FIGS. 2 and 3, the thickness measurementcartridge 100 may also include a thickness or anvil probe 130 that ismounted within the cartridge body 102. More specifically, as can be seenin FIG. 3, the anvil probe 130 may include a first portion 132 that ismounted within the cartridge body 102 and a second deflectable portion134 that protrudes upwardly from the cartridge body 102 for contact withthe underside 19 of the anvil 15. The anvil probe 130 may be fabricatedfrom metal or other suitable material and may be associated with asecond strain gauge 140 that is mounted in the cartridge body 102. Thefirst and second strain gauges 120, 140 may each be coupled to a batteryor other source of electrical power 150, an amplifier 152, adigital-to-analog converter 154, a conventional central processing unit“CPU” 156, and a display unit 158. The battery 150, amplifier 152, theconverter 154, CPU 156 and display unit 158 may be housed within thehandle assembly 20. Each strain gauge may have its own amplifier. Thefirst and second strain gauges 120, 140 and the source of electricalpower 150, amplifier, 152, converter 154 and CPU 156 may collectivelyform an output generator generally designated as 118. In alternativeembodiments, the CPU 156 may also be coupled to a wireless signalgenerator 160 that transmits the thickness data to a remote (i.e., notsupported by the handle assembly 20) monitor 162. See FIG. 5. Themeasurement cartridge 100 may be formed with a pin and socket connection143 to facilitate electrical communication between the second straingauge 140 and conductors 21 in the elongate channel 17 that extendthrough the shaft 18 and are ultimately coupled to the CPU 156 and/orsource of electrical power 150.

Operation of a thickness measurement cartridge 100 of variousembodiments of the present invention will now be described withreference to FIGS. 1, 3, 4, and 5. Prior to installing a conventionalstaple cartridge into the elongate channel 17 of the instrument 10, thesurgeon may first install the thickness measurement cartridge 100 intothe elongate channel 17. The thickness measurement cartridge 100 may befabricated with retention features that are commonly found onconventional staple cartridges to removably retain the thicknessmeasurement cartridge 100 within the elongate channel 17. Wheninstalled, a pin and socket connector or other arrangement may connectthe second strain gauge 140 to the source of electrical power 150 andamplifier 152.

In laparoscopic and endoscopic surgical procedures, a small incision orpuncture is made in the patient's body to provide access for a tube orcannula device. Once extended into the patient's body, the cannulaallows insertion of various surgical instruments to perform the surgery.After the surgeon has installed the thickness measurement cartridge 100in the elongate channel 17, the surgeon may then insert the implement 22through the cannula (not shown) so that a portion T′ of the tissue “T”to be transected is positioned between the underside 19 of the anvil 15and the measurement cartridge 100. See FIG. 3. The surgeon then movesthe closure trigger 26 towards the pistol grip 36 to move the closuretube 24 in a known manner to pivot the anvil 15 in a closing direction.As the anvil 15 is pivoted in the closing direction, a portion of thetissue “T” to be transected is clamped between the underside 19 of theanvil 15 and the nodule 110. As can be most particularly seen in FIGS. 3and 4, a pivot protrusion 104 may be formed on the underside of thecartridge body 102 to rest on the bottom of the elongate cartridge 17 tothereby enable the cartridge body 102 to pivot thereon.

As the anvil 15 begins to clamp the tissue “T” between the underside 19of the anvil 15 and the nodule 110, the first strain gauge 120 is placedunder load and may act as a resistor, such that, as the load that isapplied to the first strain gauge 120, the first strain gauge 120 eitherincreases or decreases the amount of resistance to the electricitysupplied to it from the source of electrical power 150. The amplifier152 amplifies the signal from the first strain gauge 120 and feeds theamplified signal into the digital-to-analog converter 154 that changesraw current into digital data. The digital data is then sent to the CPU156 which interprets the digital signal and mathematically transformsthe data into a first amount of strain or load which is displayed by thehandle display 158 and/or is sent to a wireless signal generator 160which wirelessly transmits the data to a remote monitor 162. See FIG. 5.The surgeon continues to close the anvil 15 until the display indicatesthat the tissue “T” within the first and second jaws 14, 16 has beenclamped under a predetermined amount of clamping load. For example, thepredetermined amount of clamping load or force may be eight grams. Suchforce may not, for example, damage the tissue “T”, but may provide areference point for repeatability purposes.

As the anvil 15 is being closed, the undersurface 19 of the anvil 15starts to impart a load onto the anvil probe 134 which is conveyed tothe second strain gauge 140 located in the cartridge 100. The amplifier152 amplifies the output signal from the second strain gauge 140 andfeeds the amplified signal into the digital-to-analog converter 154 thatchanges raw current into digital data. The digital data is thentransmitted to the CPU 156 which interprets the digital signal andmathematically transforms the data into a tissue thickness that isdisplayed on the handle display 158 and/or is transmitted to thewireless signal generator 160 for sending to a remote monitor 162. Afterthe surgeon has determined the thickness “t” of the tissue to betransected, the implement portion 22 is withdrawn to enable thethickness measurement cartridge 100 to be replaced with the appropriatestaple cartridge. The measurement cartridge 100 may then be resterilizedfor the next procedure or simply disposed of.

In an alternative embodiment as depicted in FIGS. 6 and 7, themeasurement cartridge 100′ lacks the nodule and the first strain gaugethat was included in the measurement cartridge 100 as described above.This embodiment may only be equipped with a strain gauge 140′. Thus, inthis embodiment, the output generator 118′ may comprise the source ofelectrical power 150, the strain gauge 140′, the amplifier 152, theconverter 154, and the CPU 156. Otherwise, cartridge 100′ may besubstantially identical to cartridge 100. FIG. 7 is a schematic drawingof the interface between the strain gauge 140′ and the CPU 156. In thisembodiment, the CPU 156 employs an algorithm that compares the strainvalues over time and waits until the strain is no longer changing withina desired delta, before it displays the final load reading or calculatedtissue thickness “t” on the display. In addition, a switch 164(mechanically or electrically activated) could be associated with theclamping trigger 26 for detecting the position of the clamping trigger26. The switch 164 may communicate with the CPU 156 such that the CPU156 would not start to process the strain loads until the clampingtrigger 26 reached a predetermined position.

FIGS. 8-12 illustrate another surgical instrument 300 in the form of agrasper 302 that may employ various unique and novel features of variousembodiments of the present invention. Such graspers 302 are known in theart and, therefore, the known features thereof, will not be discussed ingreat detail herein beyond what may be needed to fully understand andappreciate various embodiments of the subject invention. Examples ofsuch devices are disclosed in U.S. Pat. Nos. 6,117,158 and 5,735,874,the disclosures of which are herein incorporated by reference.

As can be seen in FIG. 8, the grasper 302 includes an end effector 312that has a first jaw 314 and a second jaw 316 that are operably mountedto a grasper rod 400 that protrudes distally from a handle assembly 320.As is known, a proximal portion 402 of the grasper rod 400 may berotatably supported within the handle assembly 320 and coupled to arotation knob 330 rotatably supported on the handle assembly 320. Sucharrangement permits the surgeon to rotate the grasper rod 400 (and jaws314, 316) relative to the handle assembly 320. As can also be seen inFIG. 8, the grasper rod 400 extends through a closure tube 324 that alsoprotrudes from the handle assembly 320.

As is known in the art, as the jaws 314 and 316 are pivotally coupled toa distal end 404 of the grasper rod 400 and may be retained in the openposition illustrated in FIG. 8 by a spring arrangement (not shown). Thejaws 314 and 316 are caused to close when their respective proximal ends315, 317 are brought into contact with a distal end 325 of the closuretube 324 as the grasper rod 400 is drawn in the proximal direction inresponse to the actuation of a closure trigger 326 attached to thehandle assembly 320. As can be seen in FIG. 8, the closure trigger 326is pivotally mounted on a pivot rod 328 for selective pivotal traveltherearound. The closure trigger 326 has an arcuate follower arm 340attached thereto that is constrained to pivot along an arcuate pathwithin the handle assembly 320 as the closure trigger 326 is pivotedbetween the open position shown in FIG. 8 and a closed position whereinthe proximal end 327 of the pivot trigger 326 is substantially adjacentto a grip portion 336 of the handle assembly 330. Supported within thehandle assembly 320 is a closure spring 342 that is arranged to engagethe distal end of the follower arm 340 to bias the closure trigger 326in the open position. In various embodiments, the grasper 320 mayfurther include a locking trigger assembly 350 for locking the closuretrigger 326 and ultimately the jaws 314, 316 in a specific clampingposition. The construction and operation of such locking triggerassembly 350 is known in the art and therefore will not be described indetail herein.

As can be seen in FIG. 8, the grasper 302 is provided with an outputgenerator generally designated as 500. In various embodiments, theoutput generator 500 may include a first gear 502 in the form of anarcuate arm 504 that has a series of gear teeth 510 formed on a distalend 506 thereof. A proximal end 508 is attached to the closure trigger326. The gear teeth 510 are arranged in meshing engagement with theteeth of a second or closure gear 520 which is nonrotatably coupled to abell crank 530. The second gear 520 may be rotatably supported on asecond pivot rod 514 within the handle housing 320. As can be seen inFIG. 8, a distal end 532 of the bell crank 530 has a series of crankteeth 534 formed thereon and a retainer tab 538 formed on a proximal end536 thereof. Thus, by pivoting the closure trigger 326 toward the gripportion 330, the bell crank 530 is rotated in a clockwise direction “CW”as shown in FIG. 8.

Also in this embodiment, a series of rings 550 may be formed on aportion of the grasper rod 400. The rings 550 are located on the grasperrod 400 for selective engagement with the crank teeth 534. A lug 552 isalso formed adjacent the proximal-most ring 550. As can be seen in FIGS.8 and 9, the proximal end 410 of the grasper rod 400 may be attached toa reference scale arm 560 by means of a linkage arm assembly 570. As wasdiscussed above, it may be desirable for the surgeon to be able rotatethe grasper rod 400 relative to the handle assembly 320 to facilitateaccurate positioning of the jaws 314 and 316. Thus, in variousembodiments, the proximal end 410 of the grasper rod 400 may be attachedto the linkage arm assembly by a gimble-like joint assembly, generallydesignated as 580. As shown in FIG. 9, the gimble-like joint assembly580 may include a collar 582 that has two circumferentially opposedpivot pins 584, 586 protruding therefrom. The collar 584 is received ona shoulder portion 412 of the grasper rod 400 and retained thereon by ascrew 414 that threadably engages the proximal end 410 of the grasperrod 400 as shown. Those of ordinary skill in the art will understandthat such arrangement serves to permit the grasper rod 400 to freelyrotate within the collar 582 while being attached thereto.

As can also be seen in FIG. 9, the linkage arm assembly 570 may comprisea right linkage arm 572 that is pivotally attached to the right pivotpin 584 and a left linkage arm 574 that is attached to the left pivotpin 586. The proximal end 573 of the right linkage arm 572 and theproximal end 575 of the left linkage arm 574 may be pivotally attachedto the scale arm 560 by a pivot pin 590. Thus, such arrangement enablesgrasper rod 400 to be linked to the scale arm 560 while permitting freerotation of the grasper rod 400 relative thereto. In variousembodiments, the lower end 562 of the scale arm 560 may be pivotallycoupled to handle case 320 by a pivot pin 564 to enable the scale arm560 to pivot in sync with the grasper rod 400.

As can be seen in FIG. 8, the lower portion 562 of the scale arm 560 mayalso be attached to a load applying assembly 600. In variousembodiments, the load applying assembly may comprise a pin 610 that issized to move axially within a cavity 323 formed in the handle case 321.A measurement spring 612 is located within the cavity 323 for biasingthe pin 610 in a distal direction “DD”. As will be further discussedbelow, the measurement spring 612 may be sized to apply an 8 gram orother predetermined load to close the jaws 314, 316 when the closuretrigger 326 has been pivoted to a certain position. The distal end ofthe pin 614 may be pivotally coupled to the scale arm 560 by a pin 620that is received in an elongated slot 563 formed in the bottom end ofthe scale arm. See FIGS. 10-12. A reference scale 566 may be attached toor formed on the upper end of the scale arm 560 as shown. The referencescale 566 may be provided with reference indicia 568, the purpose ofwhich will be discussed in further detail below. Also in the embodimentdepicted in FIG. 8, a shroud 630 may protrude from the bell crank 530.The shroud 630 may have a first reference window 632 therethrough. Inaddition, a window 329 is also provided through the handle case 321 toenable the surgeon to read the reference indicia 568 on the referencescale 566 that is aligned therewith. See FIG. 10.

The operation of the grasper 302 may be further appreciated fromreference to FIGS. 10-12 which schematically illustrate one method ofoperation. FIG. 10 illustrates the grasper 302 in schematic form withthe jaws 314, 316 in the fully open position. When in that position, theclosure spring 342 biases the closure trigger 326 away from the gripportion (not illustrated in FIG. 10). The closure spring 342 may besized relative to the measurement spring 612 such that the closurespring 342 is stronger than the measurement spring 612 to cause theclosure trigger 326 to be pivoted to the open position when the grasper302 is unactuated. In FIG. 10, the closure spring 342 is biasing theclosure trigger 326 in the counterclockwise “CCW” direction. As can beseen in FIGS. 8 and 10, when the grasper rod 400 is in the fully openedposition, none of the teeth 534 on the bell crank 530 are in engagementwith any of the rings 550 on the grasper rod 400 and the retention tab538 on the bell crank 530 is in contact with the lug 552 on the grasperrod 400. In addition, the end of the shroud 630 extends between thereference scale 566 and the viewing window 329 in the handle case 321 sothat the surgeon will only see the shroud 630 when looking through thewindow 329; no reference indicia 568 would be viewable in the window329.

FIG. 11 illustrates use of the grasper 302 in schematic form to measurethe thickness “t” of the tissue “T”. As can be seen in that Figure, theclosure trigger 326 has been pulled in the CCW direction against theclosing force of the closing spring 342 to cause the bell crank 530 torotate in the CW direction to move the retention tab 538 out ofengagement with the lug 552 on the grasper rod 400. When the retentiontab 538 has been moved out of engagement with lug 552, the grasper rod400 is caused to move in the proximal direction “PD” by means of scalearm 560. In particular, the lower end 562 of the scale arm 560 is movedin the distal direction by the pin 610 which causes the scale arm 560 topivot about the pivot pin 564 and pull the grasper rod 400 in theproximal direction “PD”. As the measurement spring 612 expands, theposition where the pin 610 engages the scale arm 560 in the slot 563will change—moving further from the pivot rod 564. Thus, as themeasurement spring force reduces (resulting from extension of themeasurement spring 612), the mechanical advantage of the scale arm 560would increase to maintain a constant load on the grasper jaws 314, 316.As the grasper rod 400 moves in the proximal direction “PD”, it causesthe jaws 314 and 316 to close upon the tissue “T”. In variousembodiments, the measurement spring 612 may be sized such that apredetermined amount of clamping load is applied to the tissue “T”. Forexample, in one exemplary embodiment, the measurement spring 612 issized such that approximately eight grams of closure load is applied tothe tissue “T”.

When in the tissue “T” has been clamped between the jaws 314, 316 solelyunder the clamping load of the measurement spring 612, a correspondingone of the reference indicia 568 will be aligned with the viewing window329 in the handle case 321. The surgeon can then position the closuretrigger 326 to cause the bell crank 530 and shroud 630 to move to aposition wherein the viewing window 632 in the shroud 630 is inalignment with the viewing 329 window to permit the surgeon to view thereference indicia 568 through the viewing windows 329, 632 as shown inFIG. 11. When in that position, the bell crank 530 is not influencingthe position of the grasping rod 530. The position of the grasping rod400 is solely controlled by the influence of the measuring spring 612 onthe scale arm 560 in the manner described above. Thus, when in thatposition, the surgeon is viewing the reference indicia 568 associatedwith the thickness of the tissue “T” as it is clamped between the jaws314, 316 under that predetermined load. Those of ordinary skill in theart will appreciate that the measurement spring and measurement levermay be constructed/calibrated such that the reference indicia 568correspond to the thickness of the tissue “T” that is clamped under thatload.

FIG. 12 illustrates the position of the various grasper components whenthe surgeon has completely closed the jaws 314, 316 with no tissueclamped therebetween. As can be seen in that Figure, the surgeon haspulled the closure trigger 326 to the point wherein the measurementspring 612 has biased the scale arm 560 to pull the grasper rod 400 farenough in the proximal direction “PD” to cause the jaws 314, 316 tocompletely close. When the surgeon releases the closure trigger 326, theclosure spring 342, which is stronger that the measurement spring 612,biases the closure trigger 326 to the open position. As the closuretrigger 326 rotates to the open position, it causes the bell crank 530to pivot in the CCW direction in FIG. 12 to bring the retainer tab 538into engagement with the lug 552 on the grasper rod 400 to drive thegrasper rod 400 in the distal direction “DD” until the grasper rod 400reaches the open position (FIG. 10).

Thus, various embodiments of the grasper 302 may be used in thefollowing manner. The surgeon may initially close the jaws 314, 316 toenable the implement portion 322 to be inserted through the cannula orother opening. After the implement portion 322 has been inserted intothe patient, the surgeon may release the closure trigger 326 to permitthe jaws 314, 316 to open. The surgeon may then manipulate theinstrument until the target tissue “T” is oriented between the jaws 314,316. The jaws 314, 316 may then be closed on the target tissue “T” bydepressing the closure trigger 326 towards the grip portion 336 of thehandle assembly 320. As the surgeon continues to depress the closuretrigger 326, he or she can observe the viewing window 329 in the handleassembly 320 until the reference indicia 568 which corresponds to thetissue thickness under a predetermined clamping load is viewable.Further depressing of the closure trigger 326 would further draw thegrasper rod 400 in the proximal direction “PD” by virtue of theengagement of the teeth 534 on the bell crank 530 with one or more rings550 on the grasper rod 400 and thereby apply further clamping force tothe tissue “T”. In doing so, however, the movement of the bell crank 530and shroud 630 causes the viewing window 632 in the shroud 630 to moveout of alignment with the viewing window 329 in the handle casing 321.Thus, the surgeon is unable to view the reference indicia 568 when thetissue “T” has been placed under a clamping load that is greater thanthe desired predetermined clamping load. If the surgeon desires to takea thickness reading, he or she simply must start to release the closuretrigger 326 until the window 632 in the shroud 630 once again alignswith the window 329 in the handle casing to permit viewing of thereference indicia.

FIG. 13 illustrates another surgical instrument 700 in the form of agrasper 702 that may employ various unique and novel features of variousembodiments of the present invention. In this embodiment, a conventionalgrasper arrangement may be employed. Such grasper 702 may include an endeffector 712 that has a first jaw 714 and a second jaw 716 that areoperably mounted to a grasper rod 800 that protrudes distally from ahandle assembly 720. As is known, a proximal portion 802 of the grasperrod 800 is rotatably supported within the handle assembly 720 andcoupled to a rotation knob 730 rotatably supported on the handleassembly 720. Such arrangement permits the surgeon to rotate the grasperrod 800 relative to the handle assembly 720. As can also be seen in FIG.13, the grasper rod 800 may extend through a closure tube 724 that alsoprotrudes from the handle assembly 720.

As is known in the art, the jaws 714 and 716 may be pivotally coupled toa distal end 804 of the grasper rod 800 and may be retained in the openposition illustrated in FIG. 13 by a spring arrangement (not shown). Thejaws 714 and 716 are caused to close when their proximal ends 715, 717,respectively are brought into contact with a distal end 725 of theclosure tube 724 as the grasper rod 800 is drawn in the proximaldirection in response to the actuation of a closure trigger 726 attachedto the handle assembly 720. The construction and operation of theclosure trigger and its interaction with the grasper rod 800 are knownin the art and therefore will not be discussed in detail herein.

In various embodiments, however, a strain gauge 900 may be oriented forinteraction with the grasper rod 800 such that as the grasper rod ismoved in the proximal direction “PD” by depressing the closure trigger726, the strain gauge 900 measures the strain on the closure rod 800. Ascan be seen in FIG. 14, the strain gauge 900 is coupled to a battery orother source of electrical power 910, an amplifier 912, adigital-to-analog converter 914, a conventional central processing unit“CPU” 916, and a display unit 918. In various embodiments, the straingauge 900, source of electrical power 910, the amplifier 912, converter914 and CPU 916 may be collectively referred to as an output generator,generally designated as 930. In alternative embodiments, the CPU 916 mayalso be coupled to a wireless signal generator 920 that transmits thethickness data to a remote monitor 922.

In this embodiment, the CPU 916 employs an algorithm that compares thestrain values over time and waits until the strain is no longer changingwithin a given delta for example, less than 1 to 2% variation, before itdisplays the final load reading or calculated tissue thickness “t” onthe display. Such variation may be measured in raw voltage (strain gaugeacts as a resistor to modify voltage according to how much it isstressed or pulled or compressed), deflection after the data istranslated from voltage to strain, or tissue thickness when the strainis translated into thickness. In addition, a switch (mechanically orelectrically activated) could be associated with the clamping triggerfor detecting the position of the clamping trigger. The switch 164 maycommunicate with the CPU 156 such that the CPU 156 would not start toprocess the strain loads until the closure trigger 26 reached apredetermined position.

Another feature of various embodiments of the present invention isdepicted in FIG. 14. In particular, FIG. 14 illustrates jaws 710, 720that may be used in connection with any of the grasper embodimentsdescribed herein or other conventional grasper arrangements wherein itmay be advantageous to grasp and manipulate another surgical instrumentsuch as, an endocutter or the like. In the embodiment depicted in FIG.15, the first jaw 710 may have a clamping face 711 and a distal end 712that curves downward. The second jaw 720 has a clamping face 721 and adistal end 722 that curves upwardly. A somewhat curved nodule 714 may beformed on the clamping face 711 of the first jaw 710 and anothersomewhat curved nodule 724 may be formed on the clamping face 721 of thesecond jaw 720. In this embodiment, the nodules 714, 724 may be sooriented and shaped to cooperate with the respective distal ends 712,722 of the first and second jaws 710, 720 so as to form a cradle,generally designated as 730, for receiving and supporting a portion of asurgical instrument 750 that has a substantially circularcross-sectional shape. Such arrangement serves to provide a positivesupport for the surgical instrument 750 within the first and second jaws710, 720 and enables the surgeon to accurately manipulate the instrument750 using the grasper. Those of ordinary skill in the art willunderstand that, in other embodiments of the present invention, thesizes, shapes and numbers of nodules may vary and/or the distal ends ofthe jaws may have different shapes to better form a cradle thatcorresponds to the cross-sectional shape of the instrument to be graspedbetween the jaws. Thus, the scope and protection afforded to thesevarious embodiments should not be limited to use of two nodules havingthe specific shapes illustrated in FIG. 14.

FIGS. 15-23 illustrate another surgical instrument 1000 in the form of agrasper 1002 that may employ certain unique and novel features ofvarious embodiments of the present invention. In various embodiments,the grasper 1002 may include an end effector 1012 that has a first jaw1014 and a second jaw 1016 that are operably mounted to a grasper rod1100 that protrudes distally from a handle assembly 1020. See FIG. 19.The grasper rod 1100 may be axially received within a tube 1024 that maybe rotatably affixed to the handle assembly 1020. A rotation knob 1030may be rotatably affixed to the handle assembly 1020 as shown in FIG. 19and be attached to the tube 1024 such that rotation of the rotation knob1030 relative to the handle assembly 1020 may also result in therotation of the end effector 1012 relative to the handle assembly 1020.The jaws 1014 and 1016 may be pivotally coupled to a distal end 1104 ofthe grasper rod 1100 by corresponding linkages 1106, 1108. Movement ofthe grasper rod 1100 in the distal direction “DD” will cause the jaws to1014, 1016 to pivot closed.

In various embodiments, the grasper rod 1100 may be selectively moved byactuation of a closure trigger 1026 that is pivotally supported by thehandle assembly 1020. More specifically and with reference to FIGS. 17and 18, a proximal end 1102 of the grasper rod 1100 may be attached to acalibrated spring slide 1200 housed within the handle assembly 1020. Invarious embodiments for example, the proximal end 1102 of the grasperrod 1100 may be formed with a T-shaped portion 1103 that is configuredto be received in a correspondingly shaped cavity 1204 in a distal endportion 1202 of the calibrated spring slide 1200. The calibrated springslide 1200 is configured to be movably received in an elongated opening1040 in the handle assembly 1020 and has an actuator opening 1208therein for receiving a lever arm 1028 formed on the closure trigger1026. The lever arm 1028 may also protrude through the actuator opening1208 into a corresponding opening 1212 in a window slide 1210 that isconfigured to be slidably supported within a window slide cavity 1040formed in the handle assembly 1020. The widow slide 1210 may haveblocking portions 1214 formed thereon that, as will be discussed infurther detail below, serve to block corresponding window openings 1022formed in the handle assembly 1020. Thus, by pivoting the closuretrigger 1026 toward the pistol grip portion 1025 of the handle assembly1020, the lever arm 1028 causes the calibration spring slide 1200 andthe window slide 1210 to move in the proximal “PD” direction. In variousembodiments, a window slide spring 1216 may be supported by the handleassembly 1020 to bias the window slide 1210 in the distal “DD”direction.

As can also be seen in FIGS. 16-23, the grasper 1002 may also beconfigured with a releasable lock assembly, generally designated as1220. In various embodiments, the lock assembly 1220 may comprise alever lock arm 1222 that is attached to or protrudes from the closuretrigger 1026 that is pivotally journaled on a pivot stud 1023 or othermember formed on or otherwise attached to the handle assembly 1020. SeeFIG. 16. A torque spring 1230 may also be journaled on the pivot stud1023 to apply a biasing force to the closure trigger 1026 to bias theclosure trigger 1026 to an open position as illustrated in FIG. 18. Invarious embodiments, the lever lock arm 1222 may comprise a piece ofmetal or other suitable material that is attached to the closure trigger1026 and is configured to extend into a lock cavity 1027 formed in thehandle assembly 1020. Extending into the lock cavity 1027 is a lockmember that has a serrated or toothed end 1242 that is configured toselectively engage a portion of the lever lock arm 1222 and retain itwithin the lock cavity 1027. As shown in FIGS. 16-23, a lock spring 1250may be supported in the handle assembly 1020 for biasing the lock member1240 into retaining engagement with a portion of the lever lock arm1222. To enable the clinician to selectively release the lock member1240 out of retaining engagement with the lever lock arm 1222, a releasetrigger 1260 may be provided. In various embodiments, the releasetrigger 1260 may have a proximal end 1262 portion that is slidablyreceived within a trigger cavity 1029 in the handle assembly. Theproximal end 1262 of the release trigger 1260 is also configured toextend into a cavity 1244 formed in the lock member 1240. Depressing therelease trigger 1260 toward the pistol grip portion 1025 of the handleassembly 1020 causes the proximal end 1262 of the release trigger 1260to cooperate with an angled surface 1246 within the cavity 1244 to causethe lock member 1240 to moved downwardly against the lock spring 1250 toenable the lever lock arm 1222 to be released from the lock cavity 1027.When the lever lock arm 1222 is released, the closure trigger 1026 maypivot to an open position under the influence of the torque spring 1230.

Various embodiments may further include an output generator generallydesignated as 1201. In various embodiments, the output generator mayinclude a reference dial 1270 that is rotatably supported on a dial stud1272 formed or otherwise supported within the handle assembly 1020. Thereference dial 1270 may be provided with reference indicia 1274, thepurpose of which will be discussed in further detail below. In addition,the output generator 1201 may further include drive gear 1280 may beformed or otherwise attached to the reference dial 1270 as shown in FIG.16. The drive gear 1280 is arranged for meshing engagement with gearteeth 1206 formed on the calibrated spring slide 1204. Also in variousembodiments, the output generator may, for example, include a calibratedspring 1290 provided on the distal end 1202 of the calibrated springslide 1200 and be received within a corresponding cavity 1292 in thehandle housing 1020. As will be appreciated from the discussion tofollow, the output generator 1201 in various embodiments is mechanicallyactuated or powered. As used herein, the term “mechanically actuated”means that the output generator is actuated without any electricallygenerated input.

Operation of various embodiments of the grasper 1002 may be understoodfrom reference to FIGS. 18-23. FIG. 18 illustrates the grasper 1002 in a“fully closed” and locked position. When the closure trigger 1026 is inthe fully depressed position, the lever arm 1028 is positioned withinthe lever arm cavity 1208 in the calibrated spring slide 1200 to permitthe calibrated spring slide 1200 to slide proximally under the biasingforce created by the calibration spring 1292. As the calibrated springslide 1200 moves proximally, it drives the reference dial 1270 in aclockwise direction by virtue of the meshing engagement between theteeth 1206 and the drive gear 1280. In various embodiments, thecalibrated spring 1292 may be sized such that the “0” on the referencedial 1270 is aligned with the window 1022 in the handle assembly 1020.To return to a fully open position (FIG. 19), the clinician depressesthe release trigger 1260 as shown in FIG. 23 which releases the leverlock arm 1222 and permits the closure trigger 1026 to return to the openposition under the force of the torque spring 1230. As the closuretrigger 1026 moves to the open position, the lever arm portion 1028pivots in a counterclockwise direction within the opening 1212 in thewindow slide 1210 thereby permitting the window slide 1210 to be biasedin the distal direction by the window slide spring 1216 such that theblocking portions 1214 block the windows 1022 in the handle assembly1020. In addition, the lever arm portion 1028 pushes the calibratedspring slide 1200 distally which moves the grasper rod 1100 distally toopen the jaws 1014 and 1016.

When the clinician desires to clamp the tissue “T” between the jaws1014, 1016 as shown in FIG. 21, the clinician moves the end effector1012 into position and depresses the release trigger 1260 to permit theclosure trigger 1026 to begin to be depressed. When in that position,the window slide 1210 is positioned in its distal-most position and theblocking portions 1214 thereof do not obscure the windows 1022 in thehousing assembly. As the closure trigger 1026 is depressed, thecalibrated spring slide 1200 moves proximally which draws the grasperrod 1110 proximally and causes the jaws 1014 and 1016 to clamp thetissue “T” therebetween (FIG. 21). The clinician continues to depressthe closure trigger 1026 until the closure trigger has pivoted to apoint wherein the lever arm portion 1028 biases the window slide 1210proximally to a position wherein the blocking portions 1214 block thewindows 1022 in the handle assembly 1020. See FIG. 22. The clinicianthereafter slightly releases the closure trigger 1026 to a point whereinthe reference indicia 1274 on the reference dial 1270 is viewablethrough the windows 1022 in the handle assembly 1020. See FIG. 23. Thoseof ordinary skill in the art will appreciate that the reference indiciamay be associated with a particular thickness “t” of tissue “T”. Forexample, the number 1 on the reference dial 1270 may represent anapproximate tissue thickness of 1 mm; the number 2 may represent anapproximate tissue thickness of 2 mm and so on. It will be furtherunderstood that such unique and novel arrangement enables the clinicianto obtain a thickness measurement of the tissue “T” at a predeterminedclamping load (resulting from the calibrated spring 1292). For example,the calibrated spring 1292 may be sized to apply an approximate clampingload of 8 grams/mm squared when the grasper is positioned to indicatethe tissue thickness. If the clinician “over clamps” the tissue, thewindow slide 1210 moves to a position wherein the blocking portions 1214block the windows 1022 to thereby prevent the clinician from reading thereference indicia 1274.

While the present invention has been illustrated by description ofseveral embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications mayreadily appear to those skilled in the art. Those of ordinary skill inthe art will readily appreciate the different advantages provided bythese various embodiments. For example, various embodiments of thepresent invention enable the surgeon to determine the thickness of thedesired target tissue to enable the properly sized implementations(staple cartridges, etc.) to be employed. Various embodiments are alsoconstructed to enable the surgeon to take such tissue thicknessmeasurements under a predetermined compressive load.

While several embodiments of the invention have been described, itshould be apparent, however, that various modifications, alterations andadaptations to those embodiments may occur to persons skilled in the artwith the attainment of some or all of the advantages of the invention.For example, according to various embodiments, a single component may bereplaced by multiple components, and multiple components may be replacedby a single component, to perform a given function or functions. Thisapplication is therefore intended to cover all such modifications,alterations and adaptations without departing from the scope and spiritof the disclosed invention as defined by the appended claims.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include an combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of particular pieces or parts of thedevice can be selectively replaced or removed in any combination. Uponcleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Those ofordinary skill in the art will appreciate that the reconditioning of adevice can utilize a variety of different techniques for disassembly,cleaning/replacement, and reassembly. Use of such techniques, and theresulting reconditioned device, are all within the scope of the presentapplication.

Preferably, the invention described herein will be processed beforesurgery. First a new or used instrument is obtained and, if necessary,cleaned. The instrument can then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK® bag. The container and instrument are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or higher energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument can then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

The invention which is intended to be protected is not to be construedas limited to the particular embodiments disclosed. The embodiments aretherefore to be regarded as illustrative rather than restrictive.Variations and changes may be made by others without departing from thespirit of the present invention. Accordingly, it is expressly intendedthat all such equivalents, variations and changes which fall within thespirit and scope of the present invention as defined in the claims beembraced thereby.

What is claimed is:
 1. An end effector for use with a surgicalinstrument, said end effector comprising: a first jaw; a second jaw,wherein said first jaw and said second jaw are configured to clamptissue in response to a closing motion applied to said first jaw to movesaid first jaw between an open position, a partially clamped position,and a fully clamped position; a strain gauge configured to generate afirst strain reading and a final strain reading as the tissue isclamped; a central processing unit configured to calculate thickness ofthe tissue by comparing said first strain reading and said final strainreading; and a cartridge comprising: a cartridge body configured to beremovably supported in said second jaw and defining a cartridge decksurface; and a protrusion extending from said cartridge deck surfacewherein an end of said protrusion comprises a single point on saidcartridge body that is closest to said first jaw to focus a load appliedto said cartridge toward said strain gauge.
 2. The end effector of claim1, wherein said strain gauge is positioned within a distal portion ofsaid second jaw.
 3. The end effector of claim 1, further comprising asecond strain gauge supported by said cartridge.
 4. The end effector ofclaim 3, wherein said second strain gauge is positioned within aproximal portion of said cartridge.
 5. The end effector of claim 3,wherein said central processing unit is positioned within the surgicalinstrument, and wherein said end effector comprises: a conductor in saidsecond jaw; and a pin and socket connection between said cartridge andsaid conductor such that said strain gauge can electrically communicatewith said central processing unit.
 6. The end effector of claim 1,wherein said first strain reading and said final strain reading areconfigured to be wirelessly transmitted to a remote monitor.
 7. The endeffector of claim 1, wherein said cartridge further comprises aprotrusion on an underside of said cartridge body to facilitate movementof said cartridge body when said load is applied to said cartridge body.8. A surgical end effector, comprising: a first jaw comprising a firstjaw undersurface; a second jaw, wherein said first jaw is selectivelymovable relative to said second jaw; a strain gauge supported by saidsecond jaw and configured to communicate with a central processing unitconfigured to calculate thickness of tissue; and a thickness measurementcartridge, comprising: a cartridge body configured to be removablysupported in said second jaw such that a tissue contacting surfacethereon faces said first jaw undersurface; and a pivot formation on saidcartridge body to facilitate pivotal movement of said cartridge bodyrelative to said second jaw.
 9. The surgical end effector of claim 8,wherein said pivot formation comprises an arcuate surface.
 10. Thesurgical end effector of claim 8, wherein said central processing unitis positioned within a surgical instrument coupled to said end effector,and wherein said central processing unit is coupled to said strain gaugeby a pin and socket connection that couples said strain gauge to aconductor in said second jaw that is coupled to said central processingunit.
 11. The surgical end effector of claim 8, further comprising asecond strain gauge supported by said thickness measurement cartridge.12. The surgical end effector of claim 11, wherein said second straingauge is positioned within a proximal portion of said thicknessmeasurement cartridge.
 13. The surgical end effector of claim 8, whereinsaid second jaw is configured to operably support a surgical staplecartridge therein when said thickness measurement cartridge has beenremoved therefrom.
 14. The surgical end effector of claim 13, furthercomprising a firing bar configured to sever tissue clamped between saidsurgical staple cartridge and said first jaw.
 15. The surgical endeffector of claim 12 further comprising an upstanding flexible probe armoperably coupled to said second strain gauge and extending above saidtissue contacting surface.
 16. The surgical end effector of claim 15,wherein said flexible probe arm is proximal to a tissue contact area ofsaid undersurface of said first jaw.
 17. A surgical end effector,comprising: a first jaw comprising a first jaw undersurface; a secondjaw, wherein said first jaw is selectively movable relative to saidsecond jaw; and a thickness measurement cartridge, comprising: acartridge body configured to be removably supported in said second jaw,said cartridge body defining a deck surface; a strain gauge supported bysaid cartridge body; and an upstanding flexible probe arm operablycoupled to said strain gauge and extending above said deck surface suchthat said flexible probe arm is proximal to a tissue contact area ofsaid first jaw undersurface.
 18. The surgical end effector of claim 17,further comprising another strain gauge in said second jaw.
 19. Thesurgical end effector of claim 18, wherein said strain gauge and saidanother strain gauge communicates with a central processing unitsupported by a surgical instrument coupled to said end effector.